1. Technical Field
The present invention relates to the field of mobility management services in a network utilizing the H.323 protocol and, in particular, to providing back-end services facilitating intra-zone and inter-zone terminal mobility when a mobile H.323 terminal moves within their home zone and to and between foreign zones, the back-end services including authentication and mobile terminal location database services.
2. Description of the Related Arts
In my prior United States Patent Applications bearing Ser. No. 09/642,142 (issued as the '255 patent), Ser. No. 09/642,279 (issued as the '448 patent) and 09/642,298 (issued as the '177 patent), filed Aug. 18, 2000, incorporated herein by reference as to their entire contents, there is shown in the Figures and described a real-time mobility protocol, architecture and intelligent signaling scheme for computer-readable medium for real-time mobile multimedia communications and conferencing over packet-based networks. At the time of filing those applications and as shown in FIG. 1 of each, protocols had not yet been fully defined for providing for mobility management when a mobile H.323 moves within their home zone and to foreign zones outside their home zone.
H.323 mobility management enables multimedia communications utilizing packetized data. H.323 mobility management includes the following functionality: discovery by an administrative domain of a mobile H.323 terminal and discovery by the mobile terminal of their host zone administrative domain, registration of the terminal with the domain, location of the terminal in the domain, updating administrative location databases once the mobile terminal is discovered and a move determined, call establishment for the terminal requesting a call and roaming by the terminal from zone to zone during a call.
In H.323, call establishment and termination are performed respectively before and after a call. Before and after an H.323 terminal makes a call, the terminal needs to be discovered and registered in the zone in which it is located. During a call, a mobile H.323 terminal may roam from one zone to another. There is a need for extensions to H.323 that will provide mobility back-end administrative services including the ability to administer roaming.
An H.323 gatekeeper (GK) needs to have certain additional features to support mobile users. If a normal GK defined in the H.323 standard is located proximate to an H.323 terminal and the GK does not support mobility, a mobile user or terminal will not be able to obtain the desired service.
A mobile entity can discover a mobile GK through the mobility gatekeeper advertisement (MGA) message or may send periodic gatekeeper request GRQ request messages as it moves from one point of attachment to another. If a mobile entity knows that it is in a foreign zone (or foreign network), it can use the GRQ message (extended to take care of mobility) to announce its presence and need for a GK functionality. In H.323, every administrative domain is presumed to have a GK functionality, otherwise, a visiting H.323 mobile entity will not receive service in that zone. An alternative method is for an H.323 mobile entity to analyze the MGA message sent periodically by an H.323 GK in its zone. Once a GK is determined, an endpoint is registered to the GK for admission to system access through a registration, admission and status (RAS) channel. Since in H.323, call establishment and termination are performed before and after a call, respectively, there is a need in the art for extensions in H.323 that will provide mobility back-end services (BES) including mobile terminal location update and terminal and service authentication services required for supporting a roaming mobile terminal prior to call establishment.